The routing details for YRT service changes are up on their site. Their frugality continues to show, and opportunities to build ridership with better routes and connections are largely lost. Downtown Markham will look forward to a major service cut.
https://www.yrt.ca/en/schedules-and-maps/ttc-line-1-subway-extension.aspx
Viva Purple will continue to serve York University, but only on weekdays - Saturday/Sunday, it's cut back to Richmond Hill Terminal. Viva Orange will extend to Richmond Hill, 7 days a week. Viva Purple will also run on two separate branches through central Markham - meaning half the Viva bus service on Enterprise Boulevard in Downtown Markham.
YRT will take over TTC routes 35D, 105, 107, and 165. Minor service improvements, but the main benefit would be more reliable service because of shorter routing on most of those replacements. 35D won't be replaced. Route 360 is also abolished.
Route 10 is cut back from York U to VMC.
Route 77 will serve on-street curbside stops on Highway 7 at VMC, Viva Orange and Zum 501 will use the Rapidway entrance, and all other buses will use the "SmartCentres Place Terminal at Vaughan Metropolitan Centre Station." That's terrible for bus connections.
Route 22A will be renamed Route 96. Route 26 will extend to VMC, but only during rush hours (groan).
Route 20 Jane and the YRT 165 Weston Road will be extended to York University, but they'll kick all passengers off the bus from 2PM onwards at Pioneer Village and deadhead to York University to begin the northbound run. That's really stupid - if you're headed to a late afternoon or evening class YRT will force you to transfer (to YRT routes 3, 107/107B, 96, or Viva Purple) or walk.
No mention of Viva Silver, which was supposed to operate between Vaughan Centre and Richmond Hill.